›› 2016, Vol. 36 ›› Issue (5): 9-.doi: 10.16708/j.cnki.1000-758X.2016.0052

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Anoptimalguidancemethodbasedonmultipleterminalconstraints

 LI  Chao-Bing, WANG  Jin-Lin, LI  Hai   

  1. BeijingAerospaceAutomaticControlInstitute,Beijing100854,China
  • Received:2016-05-03 Revised:2016-07-07 Online:2016-10-25 Published:2016-08-22

Abstract: Sincethethrustamplitudeofthemainengineonspacecraftisunadjustable,amultipleterminalconstrainbasedoptimalguidancemethodwasproposed,consideringthedeficiencyofsmallcorrectionangleassumptionofconventionaliterativeguidanceunderfiveterminalconstrains.Anoptimalcontrolmodelwasestablishedintheorbitinjectionorbitalcoordinateframe.Transversalityequationswaredirectlysolvedbyiterationtoobtaintheguidanceanglecommand.Theswitchonandoffinstantswerethenoptimizedtoreducetheinfluenceofunsatisfiedterminalconstraints.Besides, thefiveequivalentterminalconstraintsinthegeocentricinertialcoordinateframewerederivedandappropriateweightfactorswereadjustedtoimprovetheprecisionofnumericalsolvingofguidanceequations.Simulationsonstandardconditionsdemonstratethattheproposedguidancemethodhasincreasedtheprecisionofunsatisfiedterminalconstraintsby1595355m,comparedwiththeconventionaliterativeguidance.TheMonteCarlosimulationsshowtheadaptabilityoftheproposedmethodtotheinitialbiasofthespacecraftpositionandvelocity.

Key words: spacecraftorbittransfer, iterativeguidance, optimalcontrol, coordinatetransformation, switchonandoffinstantsoptimization, weightadjustment